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Thursday, June 2, 2011

Laughlin Junction CPLs

This little post goes out to another signal enthusiast who traveled out to CSX's GLENWOOD tower around 2003 near Pittsburgh, PA and was invited inside by the operator. I was unsure if he knew at the time, but GLENNWOOD tower and the line it served was slated for some reconfigurations by CSX that would have significant implications for the signal enthusiast community. First, here are a couple photos of GLENNWOOD after its closure in 2005.

 



So the topic of this post, Laughlin Junction, is about 2-3 miles west of Glennwood and until Glennwood closed was part of a string of back-to-back interlockings on the CSX P&W subdivision. Laughlin Junction had been the junction between the B&O overland route to New Castle and ultimately Chicago and the short spur to its downtown station in Pittsburgh. This station was used by the B&O's commuter train service which was taken over by the state in 1974 as PATrain and ultimately discontinued in 1989. I actually visited the old B&O station in 1994, but sometime between then and now it was demolished for a bank headquarters and the rail right of way converted into a bike trail.

Last June I was attending a conference in Pittsburgh (unrelated to my PRR Main Line adventures) and I had the opportunity to walk down to Laughlin Junction for some photos. Laughlin Junction was special because for a brief time it had the only "complete" B&O Color Position Light signal anywhere. Like the 6-feather junction indicator in the UK, a complete not only required all 6 orbitals, but also a full central target with the lunar Restricting \. So basically everything you see on this chart it had. Unfortunately when Glennwood tower was closed the interlocking wasn't just re-signaled, it was completely removed. CSX had been routing most of its traffic via the better equipped P&LE main line that it had acquired in 1993 and the old P&W sub was sort of left to wither. In 2007 the line was leased to the Allegheny Valley Railroad and all of the signaling was pulled out north of where Amtrak trains use the line to connect with the PRR Main at CP-BLOOM.

The effect on Laughlin Junction was that it's complete CPL on eastbound #2 track didn't need all those orbitals anymore as #2 track wasn't just lacking diverging routes at Glennwood, but it was de-signaled and turned into a storage track. Here is a little before and after shot first showing the eastbound signals with the complete CPL and the rail line to downtown Pittsburgh and then the current view with a more bare bones arrangement.





Also in the before photo is something called a steel mill which apparently used to "manufacture" goods.

So, let's take a walk around Laughlin Junction in 2009 and learn the story behind what was the last legendary complete B&O CPL. We begin on the old downtown right of way which is now a parking lot. The eastbound bracket mast is nicely framed by the invasive Trees of Heaven on either side of the old alignment.



Zoom shot of the bracket from the same angle. All 6 orbitals have been removed from the track 2 signal and even worse all the target needs to display is Stop and Restricting. Note that in America we've sacked the Health and Safety man and there is nothing stopping you from driving your oversize 4WD vehicle onto the rail right of way.



I was lucky enough to catch an Allegheny Valley Railroad train passing through the interlocking on #2 track.



The AVR was using two GP11 rebuilds to haul a single empty flatcar. After all, you never know when you might need a spare locomotive for some reason.  To the left appears to be the 440v pole line powering the various signal appliances on the line.



As the signals are approach lit the passing train gave me the opportunity to get a picture of the signals displaying twin Stop indications. Track 1 (left) is the only track that is still signaled through to the P&LE Main at Braddock and it's major customer is Amtrak's daily Capitol Limited round trip.



A close up of the rear of one of the targets shows a late model GRS junction box which indicates that this signal was installed in sometime since the 1970's even tho the bracket mast is clearly much older.



When the PATrain died the line was eventually removed and Laughlin Junction ceased being an actual junction. However while the track was removed the mast signal was not and to this day it stands as a ghost signal. Note the flat cap finial indicates that this mast was also a new install in the "modern era".




The ghost signal gave me a chance to get up close and personal with some CPL orbitals.



The colored CPL lenses look might brighter when not covered by the outer focusing lenses.



Watch out for stingy things!



The 8, 6 and 4 o'clock orbitals are used for Medium to Medium, Medium to Full and Medium to Slow routes restrictively. What makes complete CPL's so rare is the need for a signaled slow speed route back-to-back with an interlocking with a medium speed route.



I probably should have picked up this as a souvenir, but signaling kit is awfully large up close and I had to fly out and didn't want to deal with trying to carry it on in my bag.



Relay hut at Laughlin Jnuction. The pole line is in use to the east, but CTC control for this and the adjacent interlockings are delivered via satellite link. CTC commands via the sat link are translated to some older pulse code protocol to then be transmitted down the classic code line. By housing the vital interlocking equipment in remote locations, interlockings are able to be upgraded on an individual basis rather than in costly megaprojects. Also the Allegheny Valley Railroad who leases the line was also able to take over maintaining the interlocking hardware from CSX. Had CSX been running some sort of SSI sorting out which part the AVR was responsible for would have been more complicated.

The arm-thick cable heading east is probably the old pole-line bundle to what used to be Glennwood tower. The new hut houses the satellite link gear as well as components for the audio frequency track circuits installed on the bi-directional single track between here and BRADDOCK interlocking. 



Laughlin Junction is exactly 325 miles from the B&O Railroad museum in Baltimore. For those of you who don't know that means this is measured from the zero point of the very first railroad ever built in North America.



When Laughlin Jct was rebuilt for the PATrain service in the 70's or 80's it consisted of a full crossover with a single track branch at each end. While the PATrain track was removed in 2002 it remained a full crossover. When GLENNWOOD tower was closed the facing point crossover was removed leaving just a trailing crossover for access to the Glennwood Yard lead. Between 2005 and 2008 this second crossover was also removed leaving no interlocking appliances remaining on track 1. Here is one of the cable termination boxes from one of the trailing crossover's point machines.







The only interlocking appliance in service at Laughlin Junction is a single switch between #2 track and the Glennwood Yard lead. The old GRS point machine has been replaced by a new US&S M3, but the original old style electrical junction box was left intact.







Probably the coolest thing left at Laughlin Junction is a "new style" B&O CPL gantry installed in the 1980's probably due to planners assuming that the PATrain had a long life ahead of it. I'm sure CSX was happy to get the state to pay for a complete rebuild of the interlocking so no expense was spared.



The new style gantry is just like the old ones, only much more OSHA compliant.



The track 1 CPL lost its medium speed orbital when the facing crossover was removed, but the track 2 signal was not modified when the trailing crossover was removed. Track #2's signal can display Approach Medium for the next interlocking at EAST SCHENLEY 



Beyond the gantry track 2 ceases to exist as such and becomes an unsignaled running track as noted by the End TCS sign. The relay hut for the signals is new indicating it was installed when the new coded track circuits were installed east of this location. It's a shame that CPL's bit the dust before the modern style of signal gantries went into full swing. The combination of CPL and tubular aluminum really looks smart.



There was one more signal to explore and this was the CPL mast for trains coming out of the back end of Glennwood Yard. All I had to do was follow the ancient pole line leading from the relay hut. This clearly dates from before the 1980's rebuild and probably before the interlocking was first put under CTC.



At the end of the black pole line road was a relay cabinet and a battery box.



Which connected to an old syle CPL mast signal with no orbitals. Also note the case for an signal post telephone which is probably out of service.



Old style CPL's can be identified through their larger, fluted and non-corrosion resistant terminal case.



The switch into Laughlin Jct is for slow speed movements so this signal needs no orbitals.



Taking a step back you can see the signal is illuminated with a STOP aspect. Because the track behind me is not circuited the signal cannot be approach lit.



Well this ends out little walk around Laughlin Junction. Hopefully at some point I can get around to posting those interior photos I obtain of GLENNWOOD tower. You can view the entire set of photos here, but be prepared to scroll down through several other interlockings worth of pics.

So there you have it.  Due to change in traffic patterns the last complete complete B&O CPL vanished from the earth.  However, due to the same forces of efficiency and capacity enhancement the complete CPL would rise from the ashes and as Yoda would say...there is another. ;-)

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